| // Ceres Solver - A fast non-linear least squares minimizer |
| // Copyright 2015 Google Inc. All rights reserved. |
| // http://ceres-solver.org/ |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are met: |
| // |
| // * Redistributions of source code must retain the above copyright notice, |
| // this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above copyright notice, |
| // this list of conditions and the following disclaimer in the documentation |
| // and/or other materials provided with the distribution. |
| // * Neither the name of Google Inc. nor the names of its contributors may be |
| // used to endorse or promote products derived from this software without |
| // specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| // ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
| // LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| // CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| // SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| // CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| // POSSIBILITY OF SUCH DAMAGE. |
| // |
| // Author: sameeragarwal@google.com (Sameer Agarwal) |
| |
| #include "ceres/reorder_program.h" |
| |
| #include <algorithm> |
| #include <memory> |
| #include <numeric> |
| #include <vector> |
| |
| #include "ceres/cxsparse.h" |
| #include "ceres/internal/port.h" |
| #include "ceres/ordered_groups.h" |
| #include "ceres/parameter_block.h" |
| #include "ceres/parameter_block_ordering.h" |
| #include "ceres/problem_impl.h" |
| #include "ceres/program.h" |
| #include "ceres/residual_block.h" |
| #include "ceres/solver.h" |
| #include "ceres/suitesparse.h" |
| #include "ceres/triplet_sparse_matrix.h" |
| #include "ceres/types.h" |
| #include "Eigen/SparseCore" |
| |
| #ifdef CERES_USE_EIGEN_SPARSE |
| #include "Eigen/OrderingMethods" |
| #endif |
| |
| #include "glog/logging.h" |
| |
| namespace ceres { |
| namespace internal { |
| |
| using std::map; |
| using std::set; |
| using std::string; |
| using std::vector; |
| |
| namespace { |
| |
| // Find the minimum index of any parameter block to the given |
| // residual. Parameter blocks that have indices greater than |
| // size_of_first_elimination_group are considered to have an index |
| // equal to size_of_first_elimination_group. |
| static int MinParameterBlock(const ResidualBlock* residual_block, |
| int size_of_first_elimination_group) { |
| int min_parameter_block_position = size_of_first_elimination_group; |
| for (int i = 0; i < residual_block->NumParameterBlocks(); ++i) { |
| ParameterBlock* parameter_block = residual_block->parameter_blocks()[i]; |
| if (!parameter_block->IsConstant()) { |
| CHECK_NE(parameter_block->index(), -1) |
| << "Did you forget to call Program::SetParameterOffsetsAndIndex()? " |
| << "This is a Ceres bug; please contact the developers!"; |
| min_parameter_block_position = std::min(parameter_block->index(), |
| min_parameter_block_position); |
| } |
| } |
| return min_parameter_block_position; |
| } |
| |
| #if defined(CERES_USE_EIGEN_SPARSE) |
| Eigen::SparseMatrix<int> CreateBlockJacobian( |
| const TripletSparseMatrix& block_jacobian_transpose) { |
| typedef Eigen::SparseMatrix<int> SparseMatrix; |
| typedef Eigen::Triplet<int> Triplet; |
| |
| const int* rows = block_jacobian_transpose.rows(); |
| const int* cols = block_jacobian_transpose.cols(); |
| int num_nonzeros = block_jacobian_transpose.num_nonzeros(); |
| vector<Triplet> triplets; |
| triplets.reserve(num_nonzeros); |
| for (int i = 0; i < num_nonzeros; ++i) { |
| triplets.push_back(Triplet(cols[i], rows[i], 1)); |
| } |
| |
| SparseMatrix block_jacobian(block_jacobian_transpose.num_cols(), |
| block_jacobian_transpose.num_rows()); |
| block_jacobian.setFromTriplets(triplets.begin(), triplets.end()); |
| return block_jacobian; |
| } |
| #endif |
| |
| void OrderingForSparseNormalCholeskyUsingSuiteSparse( |
| const TripletSparseMatrix& tsm_block_jacobian_transpose, |
| const vector<ParameterBlock*>& parameter_blocks, |
| const ParameterBlockOrdering& parameter_block_ordering, |
| int* ordering) { |
| #ifdef CERES_NO_SUITESPARSE |
| LOG(FATAL) << "Congratulations, you found a Ceres bug! " |
| << "Please report this error to the developers."; |
| #else |
| SuiteSparse ss; |
| cholmod_sparse* block_jacobian_transpose = |
| ss.CreateSparseMatrix( |
| const_cast<TripletSparseMatrix*>(&tsm_block_jacobian_transpose)); |
| |
| // No CAMD or the user did not supply a useful ordering, then just |
| // use regular AMD. |
| if (parameter_block_ordering.NumGroups() <= 1 || |
| !SuiteSparse::IsConstrainedApproximateMinimumDegreeOrderingAvailable()) { |
| ss.ApproximateMinimumDegreeOrdering(block_jacobian_transpose, &ordering[0]); |
| } else { |
| vector<int> constraints; |
| for (int i = 0; i < parameter_blocks.size(); ++i) { |
| constraints.push_back( |
| parameter_block_ordering.GroupId( |
| parameter_blocks[i]->mutable_user_state())); |
| } |
| |
| // Renumber the entries of constraints to be contiguous integers |
| // as CAMD requires that the group ids be in the range [0, |
| // parameter_blocks.size() - 1]. |
| MapValuesToContiguousRange(constraints.size(), &constraints[0]); |
| ss.ConstrainedApproximateMinimumDegreeOrdering(block_jacobian_transpose, |
| &constraints[0], |
| ordering); |
| } |
| |
| VLOG(2) << "Block ordering stats: " |
| << " flops: " << ss.mutable_cc()->fl |
| << " lnz : " << ss.mutable_cc()->lnz |
| << " anz : " << ss.mutable_cc()->anz; |
| |
| ss.Free(block_jacobian_transpose); |
| #endif // CERES_NO_SUITESPARSE |
| } |
| |
| void OrderingForSparseNormalCholeskyUsingCXSparse( |
| const TripletSparseMatrix& tsm_block_jacobian_transpose, |
| int* ordering) { |
| #ifdef CERES_NO_CXSPARSE |
| LOG(FATAL) << "Congratulations, you found a Ceres bug! " |
| << "Please report this error to the developers."; |
| #else // CERES_NO_CXSPARSE |
| // CXSparse works with J'J instead of J'. So compute the block |
| // sparsity for J'J and compute an approximate minimum degree |
| // ordering. |
| CXSparse cxsparse; |
| cs_di* block_jacobian_transpose; |
| block_jacobian_transpose = |
| cxsparse.CreateSparseMatrix( |
| const_cast<TripletSparseMatrix*>(&tsm_block_jacobian_transpose)); |
| cs_di* block_jacobian = cxsparse.TransposeMatrix(block_jacobian_transpose); |
| cs_di* block_hessian = |
| cxsparse.MatrixMatrixMultiply(block_jacobian_transpose, block_jacobian); |
| cxsparse.Free(block_jacobian); |
| cxsparse.Free(block_jacobian_transpose); |
| |
| cxsparse.ApproximateMinimumDegreeOrdering(block_hessian, ordering); |
| cxsparse.Free(block_hessian); |
| #endif // CERES_NO_CXSPARSE |
| } |
| |
| |
| void OrderingForSparseNormalCholeskyUsingEigenSparse( |
| const TripletSparseMatrix& tsm_block_jacobian_transpose, |
| int* ordering) { |
| #ifndef CERES_USE_EIGEN_SPARSE |
| LOG(FATAL) << |
| "SPARSE_NORMAL_CHOLESKY cannot be used with EIGEN_SPARSE " |
| "because Ceres was not built with support for " |
| "Eigen's SimplicialLDLT decomposition. " |
| "This requires enabling building with -DEIGENSPARSE=ON."; |
| #else |
| |
| // This conversion from a TripletSparseMatrix to a Eigen::Triplet |
| // matrix is unfortunate, but unavoidable for now. It is not a |
| // significant performance penalty in the grand scheme of |
| // things. The right thing to do here would be to get a compressed |
| // row sparse matrix representation of the jacobian and go from |
| // there. But that is a project for another day. |
| typedef Eigen::SparseMatrix<int> SparseMatrix; |
| |
| const SparseMatrix block_jacobian = |
| CreateBlockJacobian(tsm_block_jacobian_transpose); |
| const SparseMatrix block_hessian = |
| block_jacobian.transpose() * block_jacobian; |
| |
| Eigen::AMDOrdering<int> amd_ordering; |
| Eigen::PermutationMatrix<Eigen::Dynamic, Eigen::Dynamic, int> perm; |
| amd_ordering(block_hessian, perm); |
| for (int i = 0; i < block_hessian.rows(); ++i) { |
| ordering[i] = perm.indices()[i]; |
| } |
| #endif // CERES_USE_EIGEN_SPARSE |
| } |
| |
| } // namespace |
| |
| bool ApplyOrdering(const ProblemImpl::ParameterMap& parameter_map, |
| const ParameterBlockOrdering& ordering, |
| Program* program, |
| string* error) { |
| const int num_parameter_blocks = program->NumParameterBlocks(); |
| if (ordering.NumElements() != num_parameter_blocks) { |
| *error = StringPrintf("User specified ordering does not have the same " |
| "number of parameters as the problem. The problem" |
| "has %d blocks while the ordering has %d blocks.", |
| num_parameter_blocks, |
| ordering.NumElements()); |
| return false; |
| } |
| |
| vector<ParameterBlock*>* parameter_blocks = |
| program->mutable_parameter_blocks(); |
| parameter_blocks->clear(); |
| |
| const map<int, set<double*>>& groups = ordering.group_to_elements(); |
| for (const auto& p : groups) { |
| const set<double*>& group = p.second; |
| for (double* parameter_block_ptr : group) { |
| auto it = parameter_map.find(parameter_block_ptr); |
| if (it == parameter_map.end()) { |
| *error = StringPrintf("User specified ordering contains a pointer " |
| "to a double that is not a parameter block in " |
| "the problem. The invalid double is in group: %d", |
| p.first); |
| return false; |
| } |
| parameter_blocks->push_back(it->second); |
| } |
| } |
| return true; |
| } |
| |
| bool LexicographicallyOrderResidualBlocks( |
| const int size_of_first_elimination_group, |
| Program* program, |
| string* error) { |
| CHECK_GE(size_of_first_elimination_group, 1) |
| << "Congratulations, you found a Ceres bug! Please report this error " |
| << "to the developers."; |
| |
| // Create a histogram of the number of residuals for each E block. There is an |
| // extra bucket at the end to catch all non-eliminated F blocks. |
| vector<int> residual_blocks_per_e_block(size_of_first_elimination_group + 1); |
| vector<ResidualBlock*>* residual_blocks = program->mutable_residual_blocks(); |
| vector<int> min_position_per_residual(residual_blocks->size()); |
| for (int i = 0; i < residual_blocks->size(); ++i) { |
| ResidualBlock* residual_block = (*residual_blocks)[i]; |
| int position = MinParameterBlock(residual_block, |
| size_of_first_elimination_group); |
| min_position_per_residual[i] = position; |
| DCHECK_LE(position, size_of_first_elimination_group); |
| residual_blocks_per_e_block[position]++; |
| } |
| |
| // Run a cumulative sum on the histogram, to obtain offsets to the start of |
| // each histogram bucket (where each bucket is for the residuals for that |
| // E-block). |
| vector<int> offsets(size_of_first_elimination_group + 1); |
| std::partial_sum(residual_blocks_per_e_block.begin(), |
| residual_blocks_per_e_block.end(), |
| offsets.begin()); |
| CHECK_EQ(offsets.back(), residual_blocks->size()) |
| << "Congratulations, you found a Ceres bug! Please report this error " |
| << "to the developers."; |
| |
| CHECK(find(residual_blocks_per_e_block.begin(), |
| residual_blocks_per_e_block.end() - 1, 0) != |
| residual_blocks_per_e_block.end()) |
| << "Congratulations, you found a Ceres bug! Please report this error " |
| << "to the developers."; |
| |
| // Fill in each bucket with the residual blocks for its corresponding E block. |
| // Each bucket is individually filled from the back of the bucket to the front |
| // of the bucket. The filling order among the buckets is dictated by the |
| // residual blocks. This loop uses the offsets as counters; subtracting one |
| // from each offset as a residual block is placed in the bucket. When the |
| // filling is finished, the offset pointerts should have shifted down one |
| // entry (this is verified below). |
| vector<ResidualBlock*> reordered_residual_blocks( |
| (*residual_blocks).size(), static_cast<ResidualBlock*>(NULL)); |
| for (int i = 0; i < residual_blocks->size(); ++i) { |
| int bucket = min_position_per_residual[i]; |
| |
| // Decrement the cursor, which should now point at the next empty position. |
| offsets[bucket]--; |
| |
| // Sanity. |
| CHECK(reordered_residual_blocks[offsets[bucket]] == NULL) |
| << "Congratulations, you found a Ceres bug! Please report this error " |
| << "to the developers."; |
| |
| reordered_residual_blocks[offsets[bucket]] = (*residual_blocks)[i]; |
| } |
| |
| // Sanity check #1: The difference in bucket offsets should match the |
| // histogram sizes. |
| for (int i = 0; i < size_of_first_elimination_group; ++i) { |
| CHECK_EQ(residual_blocks_per_e_block[i], offsets[i + 1] - offsets[i]) |
| << "Congratulations, you found a Ceres bug! Please report this error " |
| << "to the developers."; |
| } |
| // Sanity check #2: No NULL's left behind. |
| for (int i = 0; i < reordered_residual_blocks.size(); ++i) { |
| CHECK(reordered_residual_blocks[i] != NULL) |
| << "Congratulations, you found a Ceres bug! Please report this error " |
| << "to the developers."; |
| } |
| |
| // Now that the residuals are collected by E block, swap them in place. |
| swap(*program->mutable_residual_blocks(), reordered_residual_blocks); |
| return true; |
| } |
| |
| // Pre-order the columns corresponding to the schur complement if |
| // possible. |
| static void MaybeReorderSchurComplementColumnsUsingSuiteSparse( |
| const ParameterBlockOrdering& parameter_block_ordering, |
| Program* program) { |
| #ifndef CERES_NO_SUITESPARSE |
| SuiteSparse ss; |
| if (!SuiteSparse::IsConstrainedApproximateMinimumDegreeOrderingAvailable()) { |
| return; |
| } |
| |
| vector<int> constraints; |
| vector<ParameterBlock*>& parameter_blocks = |
| *(program->mutable_parameter_blocks()); |
| |
| for (int i = 0; i < parameter_blocks.size(); ++i) { |
| constraints.push_back( |
| parameter_block_ordering.GroupId( |
| parameter_blocks[i]->mutable_user_state())); |
| } |
| |
| // Renumber the entries of constraints to be contiguous integers as |
| // CAMD requires that the group ids be in the range [0, |
| // parameter_blocks.size() - 1]. |
| MapValuesToContiguousRange(constraints.size(), &constraints[0]); |
| |
| // Compute a block sparse presentation of J'. |
| std::unique_ptr<TripletSparseMatrix> tsm_block_jacobian_transpose( |
| program->CreateJacobianBlockSparsityTranspose()); |
| |
| cholmod_sparse* block_jacobian_transpose = |
| ss.CreateSparseMatrix(tsm_block_jacobian_transpose.get()); |
| |
| vector<int> ordering(parameter_blocks.size(), 0); |
| ss.ConstrainedApproximateMinimumDegreeOrdering(block_jacobian_transpose, |
| &constraints[0], |
| &ordering[0]); |
| ss.Free(block_jacobian_transpose); |
| |
| const vector<ParameterBlock*> parameter_blocks_copy(parameter_blocks); |
| for (int i = 0; i < program->NumParameterBlocks(); ++i) { |
| parameter_blocks[i] = parameter_blocks_copy[ordering[i]]; |
| } |
| |
| program->SetParameterOffsetsAndIndex(); |
| #endif |
| } |
| |
| static void MaybeReorderSchurComplementColumnsUsingEigen( |
| const int size_of_first_elimination_group, |
| const ProblemImpl::ParameterMap& parameter_map, |
| Program* program) { |
| #if defined(CERES_USE_EIGEN_SPARSE) |
| std::unique_ptr<TripletSparseMatrix> tsm_block_jacobian_transpose( |
| program->CreateJacobianBlockSparsityTranspose()); |
| |
| typedef Eigen::SparseMatrix<int> SparseMatrix; |
| const SparseMatrix block_jacobian = |
| CreateBlockJacobian(*tsm_block_jacobian_transpose); |
| const int num_rows = block_jacobian.rows(); |
| const int num_cols = block_jacobian.cols(); |
| |
| // Vertically partition the jacobian in parameter blocks of type E |
| // and F. |
| const SparseMatrix E = |
| block_jacobian.block(0, |
| 0, |
| num_rows, |
| size_of_first_elimination_group); |
| const SparseMatrix F = |
| block_jacobian.block(0, |
| size_of_first_elimination_group, |
| num_rows, |
| num_cols - size_of_first_elimination_group); |
| |
| // Block sparsity pattern of the schur complement. |
| const SparseMatrix block_schur_complement = |
| F.transpose() * F - F.transpose() * E * E.transpose() * F; |
| |
| Eigen::AMDOrdering<int> amd_ordering; |
| Eigen::PermutationMatrix<Eigen::Dynamic, Eigen::Dynamic, int> perm; |
| amd_ordering(block_schur_complement, perm); |
| |
| const vector<ParameterBlock*>& parameter_blocks = program->parameter_blocks(); |
| vector<ParameterBlock*> ordering(num_cols); |
| |
| // The ordering of the first size_of_first_elimination_group does |
| // not matter, so we preserve the existing ordering. |
| for (int i = 0; i < size_of_first_elimination_group; ++i) { |
| ordering[i] = parameter_blocks[i]; |
| } |
| |
| // For the rest of the blocks, use the ordering computed using AMD. |
| for (int i = 0; i < block_schur_complement.cols(); ++i) { |
| ordering[size_of_first_elimination_group + i] = |
| parameter_blocks[size_of_first_elimination_group + perm.indices()[i]]; |
| } |
| |
| swap(*program->mutable_parameter_blocks(), ordering); |
| program->SetParameterOffsetsAndIndex(); |
| #endif |
| } |
| |
| bool ReorderProgramForSchurTypeLinearSolver( |
| const LinearSolverType linear_solver_type, |
| const SparseLinearAlgebraLibraryType sparse_linear_algebra_library_type, |
| const ProblemImpl::ParameterMap& parameter_map, |
| ParameterBlockOrdering* parameter_block_ordering, |
| Program* program, |
| string* error) { |
| if (parameter_block_ordering->NumElements() != |
| program->NumParameterBlocks()) { |
| *error = StringPrintf( |
| "The program has %d parameter blocks, but the parameter block " |
| "ordering has %d parameter blocks.", |
| program->NumParameterBlocks(), |
| parameter_block_ordering->NumElements()); |
| return false; |
| } |
| |
| if (parameter_block_ordering->NumGroups() == 1) { |
| // If the user supplied an parameter_block_ordering with just one |
| // group, it is equivalent to the user supplying NULL as an |
| // parameter_block_ordering. Ceres is completely free to choose the |
| // parameter block ordering as it sees fit. For Schur type solvers, |
| // this means that the user wishes for Ceres to identify the |
| // e_blocks, which we do by computing a maximal independent set. |
| vector<ParameterBlock*> schur_ordering; |
| const int size_of_first_elimination_group = |
| ComputeStableSchurOrdering(*program, &schur_ordering); |
| |
| CHECK_EQ(schur_ordering.size(), program->NumParameterBlocks()) |
| << "Congratulations, you found a Ceres bug! Please report this error " |
| << "to the developers."; |
| |
| // Update the parameter_block_ordering object. |
| for (int i = 0; i < schur_ordering.size(); ++i) { |
| double* parameter_block = schur_ordering[i]->mutable_user_state(); |
| const int group_id = (i < size_of_first_elimination_group) ? 0 : 1; |
| parameter_block_ordering->AddElementToGroup(parameter_block, group_id); |
| } |
| |
| // We could call ApplyOrdering but this is cheaper and |
| // simpler. |
| swap(*program->mutable_parameter_blocks(), schur_ordering); |
| } else { |
| // The user provided an ordering with more than one elimination |
| // group. |
| |
| // Verify that the first elimination group is an independent set. |
| const set<double*>& first_elimination_group = |
| parameter_block_ordering |
| ->group_to_elements() |
| .begin() |
| ->second; |
| if (!program->IsParameterBlockSetIndependent(first_elimination_group)) { |
| *error = |
| StringPrintf("The first elimination group in the parameter block " |
| "ordering of size %zd is not an independent set", |
| first_elimination_group.size()); |
| return false; |
| } |
| |
| if (!ApplyOrdering(parameter_map, |
| *parameter_block_ordering, |
| program, |
| error)) { |
| return false; |
| } |
| } |
| |
| program->SetParameterOffsetsAndIndex(); |
| |
| const int size_of_first_elimination_group = |
| parameter_block_ordering->group_to_elements().begin()->second.size(); |
| |
| if (linear_solver_type == SPARSE_SCHUR) { |
| if (sparse_linear_algebra_library_type == SUITE_SPARSE) { |
| MaybeReorderSchurComplementColumnsUsingSuiteSparse( |
| *parameter_block_ordering, |
| program); |
| } else if (sparse_linear_algebra_library_type == EIGEN_SPARSE) { |
| MaybeReorderSchurComplementColumnsUsingEigen( |
| size_of_first_elimination_group, |
| parameter_map, |
| program); |
| } |
| } |
| |
| // Schur type solvers also require that their residual blocks be |
| // lexicographically ordered. |
| return LexicographicallyOrderResidualBlocks( |
| size_of_first_elimination_group, program, error); |
| } |
| |
| bool ReorderProgramForSparseCholesky( |
| const SparseLinearAlgebraLibraryType sparse_linear_algebra_library_type, |
| const ParameterBlockOrdering& parameter_block_ordering, |
| int start_row_block, |
| Program* program, |
| string* error) { |
| if (parameter_block_ordering.NumElements() != program->NumParameterBlocks()) { |
| *error = StringPrintf( |
| "The program has %d parameter blocks, but the parameter block " |
| "ordering has %d parameter blocks.", |
| program->NumParameterBlocks(), |
| parameter_block_ordering.NumElements()); |
| return false; |
| } |
| |
| // Compute a block sparse presentation of J'. |
| std::unique_ptr<TripletSparseMatrix> tsm_block_jacobian_transpose( |
| program->CreateJacobianBlockSparsityTranspose(start_row_block)); |
| |
| vector<int> ordering(program->NumParameterBlocks(), 0); |
| vector<ParameterBlock*>& parameter_blocks = |
| *(program->mutable_parameter_blocks()); |
| |
| if (sparse_linear_algebra_library_type == SUITE_SPARSE) { |
| OrderingForSparseNormalCholeskyUsingSuiteSparse( |
| *tsm_block_jacobian_transpose, |
| parameter_blocks, |
| parameter_block_ordering, |
| &ordering[0]); |
| } else if (sparse_linear_algebra_library_type == CX_SPARSE) { |
| OrderingForSparseNormalCholeskyUsingCXSparse( |
| *tsm_block_jacobian_transpose, |
| &ordering[0]); |
| } else if (sparse_linear_algebra_library_type == ACCELERATE_SPARSE) { |
| // Accelerate does not provide a function to perform reordering without |
| // performing a full symbolic factorisation. As such, we have nothing |
| // to gain from trying to reorder the problem here, as it will happen |
| // in AppleAccelerateCholesky::Factorize() (once) and reordering here |
| // would involve performing two symbolic factorisations instead of one |
| // which would have a negative overall impact on performance. |
| return true; |
| |
| } else if (sparse_linear_algebra_library_type == EIGEN_SPARSE) { |
| OrderingForSparseNormalCholeskyUsingEigenSparse( |
| *tsm_block_jacobian_transpose, |
| &ordering[0]); |
| } |
| |
| // Apply ordering. |
| const vector<ParameterBlock*> parameter_blocks_copy(parameter_blocks); |
| for (int i = 0; i < program->NumParameterBlocks(); ++i) { |
| parameter_blocks[i] = parameter_blocks_copy[ordering[i]]; |
| } |
| |
| program->SetParameterOffsetsAndIndex(); |
| return true; |
| } |
| |
| int ReorderResidualBlocksByPartition( |
| const std::unordered_set<ResidualBlockId>& bottom_residual_blocks, |
| Program* program) { |
| auto residual_blocks = program->mutable_residual_blocks(); |
| auto it = std::partition( |
| residual_blocks->begin(), residual_blocks->end(), |
| [&bottom_residual_blocks](ResidualBlock* r) { |
| return bottom_residual_blocks.count(r) == 0; |
| }); |
| return it - residual_blocks->begin(); |
| } |
| |
| } // namespace internal |
| } // namespace ceres |